"I mean the bottom line, the crux of this entire issue, is that people were working with a foreign government who you know is not working in our best interests to destabilize our elections and to destabilize our country," McAuliffe told David Axelrod on "The Axe Files," a podcast from the University of Chicago Institute of Politics and CNN.

"If we find that any US citizen was involved in this, it's treason," he said.

"We'll see where it goes," the Virginia Democrat said of Mueller's indictments of Paul Manafort, Rick Gates, and George Papadopoulos this week. Papadopoulos, who served as a foreign policy adviser for the Trump campaign, pleaded guilty to making a false statement to the FBI after he lied about his interactions with foreign officials close to the Russian government. Manafort and Gates pleaded not guilty.

McAuliffe said he thinks someone with knowledge of the US election "had to give (the Russians) a roadmap of who to talk to, what names to put on memos and things." And while he doesn't believe there's evidence yet of treason, he does think the impact of the Russia's interference in the 2016 campaign is apparent.

Read More

"Look at the destabilization in our country today that's been wrought because of this," McAullffe said. "You know we've got issues with NATO today. Look at the issues going on with North Korea."

"This is just the beginning, I think, of a long series of things that are about to come," he said of Mueller's investigation.

Looking ahead to next week's election for his gubernatorial successor, McAuliffe said that he believes the Republican candidate, Ed Gillespie, is running with the "Trump playbook."

"People are happy with our economy and Ed can't run on that so he's got to take the Trump playbook and divide people," McAuliffe said.

The current Virginia governor took particular issue with Gillespie's attack ads, which warn of the MS-13 gang and sanctuary cities (which McAuliffe notes do not exist in Virginia) and tout the preservation of Confederate monuments. Some Democrats have accused Gillespie of using the ads to stoke racial fears -- an accusation with which McAuliffe agrees.

"This is not the Ed Gillespie I knew, but the Ed Gillespie (in) this campaign is racist, bigoted, hurtful," he told Axelrod. "As a candidate, you own your ads. Plain and simple."

Asked whether he harbors any aspirations of seeking the highest political office -- the presidency -- when he ends his term next year, McAuliffe said he has "no idea" what he'll be doing in 2020. He noted he plans to travel to support Democratic gubernatorial candidates, saying his focus is squarely on the 2018 races.

"It drives me wild when Democrats talk about 2020. Because if we don't have a successful night in 2018, and we're going to get redistricted ... our party and the principles we care about are going to get wiped out," he said.

However, when pressed about whether he would rule out a run, McAuliffe said he'd "never rule anything out."